We have to simplify complex numbers and I was wondering whether I did these problems correctly.

Question

1. 4i^2-2i^3 = -4+2i
2. (-i)^3 = i
3. (the square root of a -2)^6= -8
4.1/(2i)^3 = i/8

Answer 1

1. right
2. right
3. [sqrt(-2)]^6 = -8 yes if that is the question
4. right